FortWorthZoo Blog – Expedition: Education

One of the most beloved symbols of the Wild West

Once down to a few hundred individuals, 450,000 bison now live in North America

The American Bison

Nov. 30th | Posted by 3 comments

(Photo Credit: Paul Whalen)

This week I put on my cowboy hat and boots and headed out to the Texas panhandle to meet a famous symbol of the old Wild West. Its scientific name is Bison bison, but you’re probably more familiar with its two common names: bison or buffalo. Both common names refer to the same animal.

Bison live in groups called herds (Photo Credit: Discovery Education)

American bison are big animals. In fact, they’re the biggest land animals in North America. From hoof to shoulder, a bison stands 5 to almost 7 feet tall. Its curved horns alone may grow to be up to two feet long. Don’t let its size fool you; this mammal can still move! A bison may reach speeds up of to 40 miles per hour when on the run.

Bison can reach speeds of up to 40 mph when on the run. (Photo Credit: Shaun Santa Cruz)

These herbivores love to munch on grass. In a single day, one bison can eat up to almost two percent of its body weight in dry vegetation. Since an American bison usually weighs more than 1 ton, two percent of its body weight is a lot of grass! Can you use your math skills and tell me just how much two percent of 2,000 pounds is? Send your answer to for a chance to win a prize!

To supply their grassy diet, American bison live on prairies and grasslands. Bison herds are important keystone species for these habitats. Their heavy hoofs and hunger for grass actually helped build the plains that cover mid-America. The diet and movement of bison kept trees and other large plants from growing in these areas. Because of bison and other keystone species, such as prairie dogs, many animals have found a home on American prairie land. One of those animals is our friend the black-footed ferret!

Bison live on prairies and grasslands to supply their vegetarian diet. (Photo Credit: Fort Worth Nature Center)

On my visit to the Texas panhandle, I came face-to-face with the last remaining relatives of the great southern plains bison herd. Texas Parks and Wildlife owns the herd at Caprock Canyons State Park, but that wasn’t always the case.

As settlers began to move west across the Great Plains toward California in the 1800s, they decimated the American bison population. Due to a lack of hunting regulations, an estimated 50 million bison were killed for sport and for food. A few hundred individuals were all that remained near the close of the 1800s.

Conservationist and rancher Charles Goodnight didn’t like what was happening to bison, so he decided to do something about it. With encouragement from his wife Mary, Goodnight captured a few bison calves in 1878. By 1887, he had 13 bison. In the 1920s, Goodnight’s bison herd reached its peak at 200 individuals.

In 1905, President Theodore Roosevelt and William Hornaday founded the American Bison Society, headquartered at the Bronx Zoo. The organization joined with private landowners and other conservationists to create reserves for bison herds and to raise awareness about the declining bison numbers. Goodnight’s herd was one of a handful of herds formed by private landowners to protect the remaining American bison. The surviving bison from these conservation herds were later used to repopulate American prairie lands.

Private landowners and other conservationists created reserves where the bison could roam and reproduce in safety, allowing population numbers to bounce back. (Photo Credit: Fort Worth Nature Center)

Also instrumental in saving the bison was the protection of the bison herd at Yellowstone National Park. The herd at Yellowstone remains the only original wild herd in existence. Thanks to government protection, ranchers and other conservationists never moved this herd from its original range. Yellowstone is currently home to a population of around 3,000 bison.

The bison herd at Yellowstone National Park never had to be moved from its original range. Today the herd numbers 3,000 bison and is the only original wild herd in existence. (Photo Credit: Discovery Education)

Though Goodnight passed away in 1929, his bison herd stayed in its original range near JA Ranch in the Texas panhandle. Goodnight’s dream had been for the state of Texas to take over his bison herd. However, that didn’t happen until 1994 when the Texas Parks and Wildlife Department (TPWD) became aware that the herd was composed of pure bison, meaning the animals had not mixed with any other species. In the past, ranchers often bred bison with cattle. The goal of breeding the two species together was to try and get the best qualities from each animal, resulting in a hybrid. Since there are not many genetically pure bison left that do not have any cattle genes, Goodnight’s herd is rare. Blood tests also revealed that the herd has unique genetic material that is not present in any other American bison.

In 1997, TPWD took on the tough task of capturing and moving the 36 remaining bison from Goodnight’s herd. Easier said than done since these animals weigh an average of 2,000 pound each! Luckily the transportation went smoothly and all 36 bison arrived safely at their new home in Caprock Canyons State Park.

Charles Goodnight's herd moved to Caprock Canyon State Park in 1997. The herd now has over 80 bison. (Photo by Earl Nottingham © TPWD)

The herd at Caprock Canyons has more than doubled in size since the state took over. Today, more than 450,000 bison roam North American prairies and grasslands. It’s certainly excellent progress, but we need to be careful to make sure population numbers remain stable. The International Union for the Conservation of Nature (IUCN) lists the American bison as “near threatened” on its Red List of Threatened Species. However, as long as the conservation herds and wild herds stay healthy, American bison should be safe.

Can’t make it to Caprock Canyons State Park to get a peek at bison? Not a problem! The Fort Worth Nature Center also has a bison herd. The beginnings of this herd came from the Wichita Mountains Wildlife Refuge in Oklahoma. From those original bison, the herd has continued to grow. Some members of the Nature Center’s herd actually used to live here at the Fort Worth Zoo. The Zoo‘s bison were released onto the Fort Worth Nature Center’s property in 2007. They’ve been living there happily ever since. Check the Fort Worth Nature Center website for more information on how you can visit and see these amazing creatures for yourself.

This bison was part of the small herd that used to live at the Fort Worth Zoo. The Zoo's bison were released at the Fort Worth Nature Center in 2007. (Photo Credit: Fort Worth Nature Center)

What can you do to help make sure the bison stays safe on American land?

  • Go see these majestic animals in person, but remember to never get close to a bison herd. These animals are fast, and they may charge at you if they feel threatened.
  • Support organizations that are dedicated to helping secure a future for the American bison, such as the Fort Worth Nature Center, Caprock Canyons State Park and Yellowstone National Park.
  • Educate others about this story of conservation success. If we can help bring back bison, we can also help other endangered species.

Yeehaw! Thanks for all you do to help save this planet’s wildlife! Don’t forget to tell me what you’re doing to conserve by dropping me a note at Sam’s Inbox ( Until next time … happy exploring!



Breeding: (noun) the production of offspring
Compose: (verb) to be a part of something
Conservation: (noun) the careful use of a natural resource so we can enjoy it now and have enough of it to enjoy in the future.
Dedicated: (adjective) completely committed to something, such as a cause or goal
Decimate: (verb) to destroy
Found: (verb) to set up or establish something new
Genetic material:
(noun) the materials in an organism that play an important role in determining its structure and nature, such as DNA molecules and genes
Herbivore: (noun) an animal that feeds primarily on grass and other plants
Herd: (noun) a number of animals that travel and feed together
Hybrid: (noun) the offspring of two different plant or animal species bred together in order to create a new animal with specific genetic characteristics
Instrumental: (adjective) useful or helpful
Keystone species: (noun) species that play an important role in ecosystems by influencing the structure of habitats and the animals that live in these habitats
Majestic: (adjective) impressive, regal, grand
Mammal: (noun) a warm-blooded animal with a backbone that breathes air and has hair at some point in its life
Original: (adjective) existing from the beginning, the first
Peak: (noun) top, highest point
Prairie: (noun) a treeless area that is covered by grass
Pure: (adjective) of unmixed descent or ancestry
Rare: (adjective) uncommon, not happening very often
Regulation: (noun) a law or rule prescribed by authority
Repopulate: (verb) to populate again, to return to an area where one once lived
Reserve: (noun) a tract of public land set apart for a special purpose
Secure: (verb) to make certain, ensure
Species: (noun) a group of individuals having some common characteristics or qualities
Ton: (noun) a unit of weight equaling 2,000 pounds
Transportation: (noun) the act of moving something to a different location
Unique: (adjective) the only of its kind
Vegetation: (noun) plant life


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    3 comments Add a comment

    1. Rick Shepherd

      Thank you, Safari Sam, for this wonderful essay on Bison bison. I will make a point this coming year to visit the herd at the Caprock Canyons State Park.We very much appreciate your inclusion of the Fort Worth Nature Center & Refuge’s small herd in your article. Rob Denkhaus and Suzanne Tuttle have been exceptional stewards and managers of this herd and we are fortunate to have them as Refuge Resource Manager and Nature Center Manager respectively. Although your article did not mention it, the FWNC&R herd is now also genetically pure, as attested by careful DNA analysis in the not-too-distant past.

      Kindest regards,
      Rick Shepherd, President
      Friends of the Fort Worth Nature Center & Refuge

    2. Donald Beard

      Great article on a magnificent creature! Thanks for helping to tell the “story” of Charles and Mary Ann Goodnight. It is a wonderful story that all Texans should know.

      Donald Beard
      Park Superintendent
      Caprock Canyons State Park

    3. Safari Sam

      Thanks for the encouragement! It means a great deal coming from friends at the Fort Worth Nature Center and Caprock Canyons State Park. Thank you for all YOU do for wildlife and for giving us the opportunity to see animals, like the American bison, in their natural habitats.

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